[llvm] [AMDGPU] Remove dead function metadata after amdgpu-lower-kernel-arguments (PR #126147)

[Scott Linder via llvm-commits]

slinder1 wrote:

### Merge activity

* **Feb 17, 1:26 PM EST**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/126147).


https://github.com/llvm/llvm-project/pull/126147